Variable speed transmission mechanism and automatic control therefor



Dec. 15, 1942. w B, THQMAS 2,304,862

VARIABLE SPEFD TRANSMISSION MECHANISM AND AUTOMATIC CONTROL THEREFORFiled Jan. 8, 1940 G'Sheets-Sheet l bu 827th; Wendell B. Thomas BybsHome 5 64 Dec. 15, 1942. w. B. THOMAS VARIABLE SPEED TRANSMISSIONMECHANISM AND AUTOMATIC CONTROL THEREFOR Filed Jan. 8, 1940 6Sheets-Sheet 2 Int/629202" Wendell B. T 17012905 By his Azionse s Dec.15, 1942. w THOMAS 2,304,862

VARIABLE SPEED TRANSMISSION MECHANISM AND AUTCMATIC CONTROL THEREFORFiled Jan. 8, 1940 6 Sheets-Sheet s Jnvenior Wendell B. Thomas By 1'5Afforveys Z $42 Dec. 15, 1 942. w THOMAS 2,304,862

VARIABLE SIEFD TRANSMISSION MECHANISM AND AUTQMATIC CONTROL THEREFORFiled Jan. 8, 1940 6 Sheets-Sheet 4 l5 CLUTCH SOLENOID .Jnvenior ZVendell .5. 771017905 Dec. 15, 1942.

w@ B. THOMAS VARIABLE SPEED TRANSMISSION MECHANISM AND AUTOMATIC CONTROLTHEREFOR 6 Sheets-Sheet 5 Filed Jan. 8, 1940 vinue/n zor Wendell B.TfJamas Patented Dec. 15, 1942 VARIABLE SPEED TRANSMISSION MECHA- NISMAND AUTOMATIC CONTROL THERE- FOR ' Wendell B. Thomas, Minneapolis, Minn.

Applicationjanuary 8, 1940, Serial No. 312,902

3 Claims.

My invention relates'to variablespeed transmission mechanismsand to theautomatic control thereof, and provides novel devices and combinationsof devices which include among them a selector switch mechanism which'switch-,- while primarily designed for use in conjunction withautomatic variablespeed transmission mechanisms, as a primary speedratio selector switch therefore, may be adapted to various difierentuses.

Whereas, the control mechanism, inclusive of the novel selector switchmechanism hereof, was designed primarily for use in the automaticcontrolling or variable speed power transmissionmechanisms of vehiclespropelled by internal combustion engines and is herein illustrated anddescribed primarily as a control for variable speed transmissions ofautomobiles, buses, trucks, and the like, it should be appreciated thatthis phase of the invention is readily adaptable to other types ofmechanisms. I

Among the important objects of the invention is the provision of aselector switch mechanism that is particularly adapted for use in theautomatic controlling of variable speed transmission mechanisms such asare present or may hereinafter be employed in motor-driven vehicles,such as internal combustion driven automobiles,

trucks, and buses, but which may be employed as a control element inother fields.

Another important object of the invention if the provision of a switchmechanism mbodying selective contacts and a relatively movable selectorcontact and in which contact selecting movements between the selectorcontact and selecting contacts may be brought about as a result ofrelative movements between the selector v An object of the invention isthe provision of I a control mechanism for variable speed transmissionmechanisms of automobiles and the like wherein the shifting of thetransmission mechanism from one speed ratio stage to another isaccomplished automatically in such'a manner that the vehicle engine willautomatically be op erated at its point of maximum efliciency undervarious different vehicle speed and engine load conditions, within thelimitations imposed by the movement of speed change ratios available forautomatic control.

Another important object and advantage of the invention is the provisionof an automatic electrical control mechanism for automatically shiftingthe transmission mechanism of an internal combustion engine propelledvehicle from one speed ratio change to another through two differentcoordinated controlling factors, namely vehicle speed and 'engineaccelerator position.

The above and numerous other objects and advantages of the inventionwill be made evident from the following specification, .claims, andappended drawings.

In the accompanying drawings, like characters indicate like partsthroughout the several views.

Referring to the drawings:

Fig. 1 is a fragmentary view of an internal combustion engine equippedvehicle-embodying one form of the invention, some parts being shown infull, some parts being broken away, and some parts being shown insection;

Fig. 2 is a fragmentary view on an enlarged scale of part of themechanisms shown in Fig. 1;

' Fig. 3 is an enlarged fragmentary detail view taken on line 3-3 ofFig. 1;

Fig. 4 is an enlarged fragmentary detailed view .of part of thetransmission and control mechanism of Fig. 1;

Fig. 5 is a view similar to Fig. 4, but with some of the parts in Fig. 3omitted or broken away and illustrating other portions of the mechanism;

Fig. 6 is a view similar to Fig. 5, but with some of the parts of Fig. 5broken away and showing certain other portions of the mechanism;

Fig. 7 is a diagrammatic view illustrating the electrical hook-up of thevarious elements of the transmission operating and control mechanismsof'the form of the invention shown in Figs. 1 to 6 inclusive;

Fig. 8 is an "enlarged detail view in top plan of the selective contactcarrier of Figs. 1, 2, and '7;

Fig. 9 is a perspective view illustrating a somewhat modified form ofselector switch mechanism;

Fig. 10 is a view illustrating the cylindrical the operation of amechanism when the particular form of selector switch of Fig. 9 isemployed in place of the selector switch mechanism of Figs. 1, 2, and 8;

Figs. 11 and 12 are similar views each taken on the line |||2 of Fig.13, and illustrating different positions of still another form ofselector switch mechanism; and

Fig. 13 is a detail view taken on a section line |3-|3 of Fig. 11.

Of the conventional automotive parts previously indicated in Fig. 1, theoperators seat is indicated by I5, a steering wheel by l6, floor boardsby H, the dash board by l8, the vehicle internal combustion engine whichmay be assumed to be of the gasoline burning type is indicated as anentirety by Hi, the engines intake manifold by 26, the enginescarburetor by 2|, a carburetor air cleaner by 22, and the carburetorthrottle valve by 23, the throttle valve 23, which is of the butterflytype, is shown as being controllable by the operator through the mediumof a foot actuated accelerator pedal 24, and linkage including a pushrod 25, a rock arm 26, a rigid link 21 anda bell crank 28 having one endfixed to the axis of the throttle valve 23. The accelerator pedal 24 ispivotally anchored to the floor boards at 29 and slidably engages theend of the push rod 25, which push rod works slidably through the floorl1 and is pivoted at its lower end to the outturned end of the rock arm26. valve operating link 21 is pivotally anchored at its rear end to theintermediate portion of the rock arm 26 at 36. The engines crank shaft,indicated by 3|, drives an axially aligned shaft 32 through the mediumof a centrifugal fluid type clutch or fly wheel 33 that is illustratedonly diagrammatically in Fig. 1, and which is contained within a splithousing 33a, the forward half of which is illustrated as beingintegrally formed with the engine casting. The rear half of the housing33a is bolted or otherwise rigidly secured to the forward half thereof,and is formed with a rearwardly projecting clutch hous ing 33B. Thefluid clutch, or fly wheel 33 is comprised of two substantially likesections 33c and The throttle I jecting clutch teeth or dogs 66.

journaled near its rear end portion in a transmission case bearing 36.In constant mesh with gear 35 is a larger speed reduction gear 39 thatis mounted on a jack shaft 66. The jack shaft 46 is journaled at itsopposite ends in case bearings 6|. Formed integrally with the gear 36 isanother relatively large gear 42 that is in constant mesh with arelatively small idle gear 63 that is rotatively mounted on the shaft 31in axially spaced relation to the gear 35, and which is similarly formedwith radially outwardly pro- The idle gear 43 is held against axialshifting movements on the shaft 31 by means of a pin or the like 45projecting through its hub into an annular channel 46 in the shaft 31.Mounted on the shaft 31 between the axially spaced clutch dog equippedhub of gears 35 and 43, is an axially shiftable clutch element 41. Thisclutch element 61, while free for axially shifting movements on theshaft 31, is spline keyed thereto as at 46, and is formed adjacent atopposite ends with radially inwardly projecting clutch teeth or dogs forcooperation with the clutch teeth or dogs 36 and 46. Integrally formedwith gears 39 and 62 are gears 49 and 56 that are respectivelyengageable with integrally formed gears 5| and 52. The pair of gears 5|and 52 are axially shiftable on the shaft 31, but are spline keyedthereto for common rotation therewith.

The transmission parts are shown in Fig. 4 in a neutral position and forthe purpose of shifting into the four ratios provided for, the clutchelement 41 is provided with a peripheral hannel 53 for engagement with asuitable shifter fork 56; and the common hub of gears 5| and 52 isprovided with a similar peripheral channel for engagement with a shifterfork 55.

The shifter forks 54 and 55 are respectively mounted on laterally spacedparallel solenoid armature bars 56 and 51. The armat ure bar 56 33d, thefirst noted of which is mounted fast on the crank shaft 3|, and the lastnoted of which is mounted fast on the shaft 32. In this type of device,driving engagement between the section 330 and 33d is provided by fluid,usually oil, which permits great slippage between the elements 33c and33d under minimum engine speeds and has substantially the effect of apositive nonslipping driving under medium high engine speeds. This isthe well known type of hydraulic clutch, or fly wheel, currentlyavailable as optional equipment on automobiles manufactured by theChrysler Corporation of Detroit, Michigan.

The shaft 32 drives a coaxially aligned shaft 32a through the medium ofa conventional yieldingly set friction clutch, contained within thehousing 33b, and the releasing shaft 32b of which projects through thehousing 33b and is equipped with a crank arm 32c.

The shaft 32a. projects into the transmission case 34, and is journaledin the front wall thereof in a bearing 34a. Formed integrally with theinner end of the clutch shaft 32a is a gear 35, having formed on itsrearwardly projecting hub portion a circumferentially spaced series of'clutch teeth or dogs 36. Coaxially disposed with respect to the clutchshaft 32 is a driven shaft 31 that is journaled at its forwardlyprojecting end within the hub of gear 35, and which 15 has its opposite.end portions axially slidably mounted in an opposed pair 'of solenoidcoils 56 and 59, and the armature bar 51 has its opposite end portionsaxially slidably mounted in an opposed pair of solenoid coils 66 and 6|.The solenoid coils 56, 59, 66, and 6| are alike, and are wound onnon-magnetic tubes 62, which may be assumed to be of brass, and whichtubes form eflicient guide bearings for the armature bars 56 and 51. Thesolenoids 56, 56, 66, and 6| each together with a cooperative armaturebar 56 or 51, constitute a power operated motor for shifting thetransmission mechanism each to a different speed ratio condition.

Returning of--the transmission to the neutral condition shown in Fig. 4is accomplished by means of a neutralizing mechanism indicated as anentirety by 63', which will later be described. When the solenoid coil66, representing first speed or the highest ratio of motor to vehiclespeed, is energized, the solenoid 51 will be moved toward the right inrespect to Figs. 4, 5, 6. and 7 (see particularly Fig. 6) thereby movingthe gear 52 through the mediumof the shifter fork 55,

into mesh with its cooperating gear flr'lliis will' result in driving ofthe shaft 31 from the shaft 32 through the following gears, to wit: gear35 to gear 36 to the integrally formed gear 56, which now being in meshwith gear 52 will drive the shaft 31 through said gear 52 and the splinekey driving connections therewith to the drive shaft.

The shaft 31 will now; of course, be driven at'a greatly reduced speedwith respect to the shaft 32. Moving of the pair of gears 5| and 52 backto their neutral condition as shown in Fig. 3 is accomplished aspreviously indicated through the neutralizing mechanism 63. When thesolenoid coil 6|, which represents the second speed of the transmissionmechanism, is energized, the armature bar 51 will move to the left tothe extent necessary to bring the gear into mesh with its .cooperatinggear 49, which will result in driving of shaft 31 from shaft 32 throughgears 35, 39, 49, and 5|. Energization of solenoid 58 will causearmature bar 56 to move to the right from a neutral position, which willresult in shifting of the clutch element 41 into interlocking engagementwith the clutch teeth 44 on gear 43. This shift, which represents thethird gear or ratio of the transmission mechanism results in driving ofthe shaft 31 from shaft 32 through gears 35, 39, 42, 43, and clutchelement 41. When the solenoid 59 is energized, the armature bar 56 ismoved to the left from a neutral position, with the result that theclutch element 41 will .become interlocked with the clutch teeth 36 ongear 35, and directly couple the shafts 32 and 31 together for drivingat a one to one ratio, which represents fourth speed of the transmissionmechanism.

Whereas, no attempt has been made to accurately proportion the gears inthe transmissionto represent any particular ratios, it may be assumedfor the purpose of example, that the four speeds of the transmissionmechanism are capable of an overall variation in ratio between shafts 32and 31, of from approximately three and one-third (3 /3) to one (1)ratio in low gear toa one to one (1 ton ratio in fourth gear, and thateach successive stage varies the ratio in approximately the sameproportion. It will, of course, be appreciated that the extent of speedratio variation may be varied to 'any desired extent and that theoverall variation may be divided up into any desired number of steps orstages; four speed ratio stages having been chosen merely for thepurpose of example.

The neutralizer mechanism 63 includes a pin 64 rigidly anchored to'andprojecting from the intermediate portion of the armature bar 51 and asimilar pin 65 that is rigidly anchored to and projecting from theintermediate portion of .the armature bar 56. These pins, 64 and 65,project into close relation one to the other, and are directly opposedwhen the shifter mechanism is in neutral position. For engagement withthese pins, there is provided an opposed pair of shifter fingers 66 and660.,- each of which i mounted fast on a different one of a pair ofjournaled shafts 61, The hub portions of the fingers 66 and 66a areformed with inter-meshing gear segments 68, which cause the same to movein unison, but in. opposite directions. a

The shifter fingers 66 and 66a, as will be seen particularly byreference to Fig. 3, are each of suflicient width to overlap the path ofmovement of each of the oppositely disposed pins 64 and 65. The finger66 serves to return the mechanism to neutral position from either itsfirst or third speed, and the finger 66a serves to return the mechanismto neutral position from either second or fourth. The hub.portion of thefinger 66 is integrally formed with actuating lever 69.

Manual operation of the neutralizer fingers 66 and 66a can beaccomplished by the operator through the medium of-linkage comprising abell crank 10, a rigid link 1|, a bell crank 12, a rigid link 13, a bellcrank 14, a rigid link 15, and an operating arm 16 that is looselyjournaled on the shaft 61 on which finger 66 is rigidly mounted, Themanually operated neutralizing linkage further includes a driving pin orlug 11 that is rigid on the actuating lever 69, and projects into thepath of movement of the arm 16. Manual neutralization of theintermediate mechanism from any gear, or speed ratio, can be accom-'plished by manipulating the crank 18 to move the arm 16 from the dottedline position of Fig. 4, or the full line position of Figs. 5 and 6, tothe full line position of Fig. 4, which is through engagement of arm 16with lug 11 and will cause the fingers 66 and 66a to move from andspread apart in the. position shown in Figs. 5 and (j to their closedpositions shown in Fig. 4. Of course the movement of these fingers fromtheir spread to their closed positions will, through engagement of oneof said fingers with either one of the pins 64 or 65, bemoved in eitherdirection from its neutral position to move back .to its neutral centerposition. O

For automatically moving the neutralizing fingers 66 and 66a back totheir neutral positions from any speed ratio position, the neutralizingmechanism 63 further includes a power operated device including asolenoid coil 18, magnetically responsive plunger 19, and a latchelement 88.

The solenoid coil 18 is wound on a non-magnetic tubing 8|, which forms aguide for the axially movable plunger 19. Downward movements of theplunger 19, under the influence of gravity, are limited by engagementthereof with intumed annular flange 82 at the lower end of the tube 8|,and upturned movements of the plunger 19, under the action of gravity,are limited by engagement of the plunger with a magnetic pluglike core83 that is screw threaded into the upper end of the tubing 8|. Theplunger 19. is formed with a stem 84 that works slidably through thereduced diameter 82 of the guide tube8l, and carries the latch element80, which latch element is pivoted to the stem 84 at 85 (see parsticularly Fig. 4). The latch element 53 is normally dropped to its lowerportion, shown by full lines in Fi 4, and is provided at its lower endwith a latch lug 86 that is normally disposed in the path of movement ofthe free end of the actuating lever 69. The latch element 88 is normallymaintained in the position shown by full lines in Fig. 4', and whereinits lug 86 is in the path of movement of the free end of the lever 69,by means of a spring 81, movements in this direction being limited byengagement of the element 80 with a stop 88 that is rigid with the stem84. The upper end portion of the latch element 88 above the pivot 85projects outwardly beyond the stem 84 when the latch element is in itslower position'shown in Fig. 4, but under upward movements of the stemand plunger 19, as a result of energization of the solenoid coil 18,this upper" end of the latch element 86 becomes engaged with the taperedcam surface of a cam lug 69, and is moved substantially into alignmentwith the plunger, which movement results in retraction of the latch lug86 out of the path of movement of the free end of the actuating lever 69(see dotted line position of latch 60 in Fig. 4).

As a power operating medium for the conventional clutch, there isprovided a clutch operated solenoid coil 90 that is equipped with amagnetically responsive plunger rod 9| that is pivotally anchored to thefree end of the clutch release arm 320 at 92. Under energization of thesolenoid 90, the plunger 9| is retracted into the solenoid coil and thismovement causes the clutch release crank arm 320 to move from its clutchset position shown by full lines in Figs. 1 and 7, to

its clutch release position shown by dotted lines in Figs. 1 and 7.

The selector switch shown in Figs. 1, 2, 7, and 8, and which isindicated as an entirety by 93, includes a plurality of selectivecontacts 94, 95, 90, and 91, and a selector contact 90. The selectivecontacts 94 to 91 inclusive are carried by and mounted on a disc-likeselective contact carrier 99 in circumferentially spaced relation one toanother. This selective contact-carrying disc is mounted fast on theupper end of a tubular shaft I that is rotatively mounted in a bearingformed in the bottom of a switch housing IOI. Below the bearing of thehousing IOI, the tubular shaft I00 is equipped with a beveled gear I02,which is mounted fast thereon.

The selector contact 90 is carried by a guide bar I03 through the mediumof a spring finger I04 that is made fast, but is electrically insulatedfrom the guide bar I03. The guide bar I03 extends completely through theswitch housing IOI, is cross sectionally annular and is axially slidablymounted in guide bearings I04. This guide bar is disposed in laterallyspaced parallel relation to the contact carrying face of the disc 99 andis radial of the axis of said disc. The contact carrying disc 99 isformed of electrical insulating material and the contacts 94 to 91inclusive are embedded therein, so that the flat top surfaces thereofare flush with the top of the surrounding insulating material of thedisc, thereby dividing the exposed top surface of the disc intocircumferentially paced contact areas represented by the top faces ofthe contacts 94, 95, 90, and 91, contact spacing areas or strips I05,I00, and I01, and a neutral zone I08 of insulating material radiallyoutward of. the several selective contacts. The contacts 94 to 91inclusive are shown as extended radially outwardly from points on thedisc 99 very close to the axis thereof outwardly to the neutral area orzone I00, which zone or area, as illustrated, is located in theperipheral portion of the disc 99 and is completely annular in form. Theseveral selective contacts 94 to 91 inclusive may be of variousdifferent shapes circumferentially of the disc 99 depending on theperformance characteristics required, but for the purpose of the presentexample, have the peculiar shapes illustrated best in Fig. 8.

The relative rotary movements between the selective contact carryingdisc99 and the selector contact under variations in vehicle speed by aspeed responsive actuator is in the nature of a centrifugal governor I09that is actuated from the shaft 31 through suitable driving connectionsroughly illustrated as comprising a gear III on the shaft 31; a gear III meshed with gear III, and a flexible cable drive I I2 of thecharacter movement of the fixture I I0 on the shaft I I4. A compressionspring I I1 is interposed between the governor fixtures III and H0, andthis tends to keep the fixtures in their maximum spread relation.Rigi'dly carried by the axially slidable governor fixture H0 is a gearrack IIO that meshes with a pinion H9. The pinion H9 is mounted fast ona journaled shaft I20 carrying a beveled gear I2I that meshes with thebeveled ar I02.

Through the action of the governor and its actuating connections to therotary selective contact carrier 99, the said contact carrier will berotated to diflerent positions in response to van-- ations in vehiclespeed; the arrangement being such that the carrier will rotate throughapproximately 360 under variations in vehicle speed from zero to maximumvehicle speed.

The selector contact 09 is normally, that is when the engine is at restor idling, positioned on the neutral area I08 of the contact carrier,but under endwise shifting movements of the rod I00, the selectorcontact is movable radially of the contact carrier to the axial portionof the contact carrier whereat the selective contacts terminate. Radialoutward movements of the contact 90 with respect to the contact carrierare limited by engagement of a stop collar or the like, I22, on theguide rod I00 with the bearing I04, and the guide rod is yieldinglybiased to its radially outermost position just above described, by meansof a compression spring I29 that is contained within a dash pot I24. Theguide rod I03 is equipped within the dash pot I24 with a sealing cup I25and the said dash pot is provided with an inwardly opening check valveI20 from atmosphere and an outwardly opening check valve I21 toatmosphere. The check valve I2l permits free discharge of air from thedash pot under inward movements of the sealing cup or piston I25,whereas the inwardly opening check valve I20 restricts the inlet of airto the cylinder or dash pot I24 sufliciently to retard return movementsof the selector contact 90 to the desired extent, under the action ofspring I23.

The guide rod I00 is operatively connected to the engine's throttlevalve controlling accelerator linkage through the medium of linkagecomprising a tubular link I20 telescopically applied over the rearwardlyextended end I29 of the guide rod I00, and a rigid link I00 connectingthe closed end of the tubular link I20 to the swingin end of the rockarm 20. The links I20 and I00 are pivotally connected at IOI. By meansof this linkage, I20 to III inclusive, the rod I00 and selector contact90 will be shifted automatically with relation to the selective contactsas a result 'of accelerating and decelerating adjustments of the enginesthrottle valve by the vehicle operator and the positioning of theselector contact 90 between its two extreme positions .will beinproportion to throttle valve posigenerally employed for drivingspeedometers and tion. The slip connection aflorded bytelescoping actionof the tubular link I20 on extension I20, permits the acceleratorlinkage to be rapidly withdrawn in'a direction of deceleration rapidlyand independently of the selector contact which in-suchinstances will bereteurned by the spring I20 at relatively retarded speed. However, in adirection of acceleration, the selector contact will always be advancedin direct proportion. to the rapidity of acceleration.

From the description of the selector switch mechanism 90, it will beevident that there are trifugal action and thereby cause upward slidingtwo distinct adjusting movements of the selective vice versa, and thatthese two movements are on 7 two different paths that are angularlydisposed one with respect to the other. Furthermore, it

will be evident that the one of these movements is rotary, which causesa relative movement between the selective contacts 94 to 91 inclusive,and the selector contact 98, on a rotary path as a result of vehiclespeed variation; whereas the other movement, which isin this instancethe direct result or changed accelerator positions, is on a straightline path which path is angularly disposed with respect to the rotarypath.

Preferably th selector switch mechanism controls the power-operatedshifting' mechanism.

through the of relay switch mechanisms RI, R2, R3, R4, each of whichrepresents a difiernt speed ratio of the transmission mechanism. Each ofthe relays RI to R4, inclusive, include cooperating normally openswitches l33, I34, and 135 and normally closed switches I36, I31, and1338.

Operation of Figs. 1 to 8 inclusive will be positioned as shown by fulllines in Figs.

1 to l inclusive, 7 and 8, and by reference to Fig.

8 it will be seen that under the conditions just named, the selectorcontact 98 will be positioned in the neutral area H38 of the selectorcontact carrying disc 89, but in radial alignment with the radiallystraight side of selectivecontact 94. At this point, attention isdirected to the fact-that on Fig. 8 broken radial lines indicate variousdifierent degrees of rotation of the selective contact carrying disc 99under different vehicle speeds, these broken radial lines being markedadjacent the periphery of the disc 99 in numerals representing speed inmiles per hour. By reference to Fig. 8, it will be seen that when thevehicle is stationary the disc 33 will be positioned with the radialline representing zeromiles per hour in direct alignment with the pathof travel of the selector contact 98. Under increased speed from zeroupward, the disc 93 will move in a counterclockwise direction withrespect to the contact From this it will be seen from the position ofthe parts illustrated in Fig. 8, the contact 88 is in alignment with thelowest speed position of the first speed selective contact 94.

Assuming now that the motor of the vehicle has been started, and isrunning at idle, operation of the vehicle in a forward direction will'beas follows: The operator will first move the lever 78 from the positionshown by full lines in Figs. 1 and 7 to the dotted line positions shownin Figs. 1 and 7, which will in turn result in mechanically moving thelever l6 to its dotted line position of Fig. 4, wherein it is free f\thepin or lug ll of Fig. 4. This leaves the neutralizing fingers 66 and660. free to be spread apart. Another function resulting from shiftingof the manual neutralizing lever ill to its forward position is theautomatic simultaneous closing of a'switch I32, which, being interppsedin the positive lead of the vehicle's storage battery B, renders'theelectrical selector and operating mechanism operative. The switch I32constitutes a master switch and is simply closed manually prior tocalling on the mechanism for automatic operation and is left in closedposition until it is desired to render the mechanism completelyinoperative.

New, to start the vehicle moving in a forward direction, the operatorwill simply step on the accelerator pedal 24 to gradually open theengines throttle valve and increase the speed of the engine. As thethrottle valve is opened under the action of the accelerator 24, theselector contact 98 "will move radially inwardly over the selectivecontact-carrying disc 99 from its position shown in Fig. 8, wherein itis on the neutral area I08, onto first speed selective contact 94. Theinitial engagement of the selector contact 98 with theselective contact94 will close a controller circuit comprising a lead I39 from thepositive side of the battery B and having interposed therein the nowclosed master switch I32 and a normally closed manually operated switchI40 and contacts IM and I42 of atWo-position switch I43, selectorcontact 98, selective contact 94, a lead I44 having interposed thereinthe nornow being energized; the normally open-switches E33, l34, N5 ofthe relay RI will be instanta-v neously closed and the normally closedswitches i36, l3] and I38 of the relay RI will simultaneously be opened.The closing of the switch I34 of the relay RI establishes a holdingcircuit for the relay RI independent of the selector switch 93, andwhich holding circuit comprises the lead I39, switch I32, switch i4Il,switch contacts MI and N2 of the switch I43, a lead M8, now closedswitch I34 of the relay RI, a lead 149, the lead'I44 through the closedswitches 436 of the inoperative relays R4, R3 and R2 to the coil of therelay RI, lead 545, contacts M8 of the switch SI, a lead i4! and back tothe negative side of the battery B. As a result of the establishing ofthis holding circuit, the coil of the relay RI will be maintainedenergized independently of the contacts of the selector switch 93. Theclosing of the switch 55 of the relay RI results in energization of theclutch-operating solenoid 90 through a circuit comprising part of thelead I39, a lead I having interposed therein the coil of the solenoid98, the plunger-like armature bar ill will be retracted into thesolenoid, thereby moving the clutchreleasing arm 320 to its'clutchrelease position; wherein the shaft 32a will be disengaged from theshaft 32, see dotted lines in Figs. 1 and 7. The solenoid armature baror plunger 9| carries a switch-operating lug I52 of insulating materialwhich, under final clutch-releasing movements, engages 'one of thespring contact fingers of a normally open switch I53 and closes saidswitch I53.- The "closing of this switch 553 establishes a circuitthrough the neutralizer solenoid I8 consisting of part of the lead I50,3, lead I54 through the now closed switch I53, the solenoid coil 18, alead I55 and part of the lead i4! returning to the battery. As a resultof I9 to its upper position does result in the closing oIa switch I56through the medium of a push contact fingers of the switch I56. Theclosing of this switch I56 completes a circuit through the gear-shiftingsolenoid 60, which circuit was previously initiated but not completed bythe closing of the switch I33 of the relay RI. This last named circuitcomprises part of the lead E39, part of the lead- I50, a lead I58 havinginterposed therein the solenoid 60, the now closed switch I33 of therelay RI, the now closed switch I56, and part of the lead I41 back tothe battery. Upon energization of the shifting solenoid 60, the armaturebar 51 will move from its centered neutral position to its extremeright-hand position shown by full lines in Fig. 6, which will result inthe shifting of the first speed gear 56 'into engagement with the firstspeed gear 50. Also under this movement of the armature bar, theneutralizer pin 64 will engage the neutralizer finger 66 and move thesame and the neutralizer finger 66a to their spread-apart positionsshown by full lines in Fig. 6. Under final shifting movements of thearmature bar 51, a rigid lug I59 thereon will engage the switch SI. andopen the cooperating contacts I46 thereof with the result that theholding circuit of the relay RI will be broken, thereby de-energizingthe relay RI and permitting the switches I33 to I38 inclusive thereof toreturn to their normal positions shown in Fig. 7 and in which positionsthe switches I33, I34 and I35 of the relay RI are open and the switchesI36, I31 and I38 of said relay RI are closed. The opening of the switchI35 of the relay RI interrupts the circuit of the clutch-operatingsolenoid 90, which permits the clutch to be yieldingly set, therebycoupling the shaft 32 to the shaft 32a, with the result that the drivenshaft 31, which is assumed to be connected to the driving wheels of thevehicle, will be driven from the engine through the first speedtransmission gears. Of course, under clutch-engaging movements of theclutchoperating elements 9|, I2 and 320, the neutralizer control switchI53 will be permitted ,to open and tie-energize the neutralizer solenoid18, which de-energization will result in returning of the plunger 19 andneutralizer latch to its lower position shown in Fig. 6. In dropp n toits lower position, the latch 80, which projects into the path ofmovement of the neutralizer lever 69, will strike the free end of saidlever and, by camming action, will move on its pivot 85 and pass aroundthe end and under the free end of the lever 69.

The vehicle is now moving in first transmission speed ratio and willremain in low until the selector contact 98 engages one of the otherselective contacts 95, 96, or 91, at which time the transmissionmechanism will be shifted first to neutral and then to the speed ratiorepresented by the next engaged selective contact, attention beingdirected at this time to the fact that, just as the contact 94represents first speed of the transmission, the contact 95 representsthe transmissions second speed, the contact 96 represents thetransmissions third speed, and the contact 91 represents thetransmissions fourth speed. Furshifting operation requires engagement ofthe selector contact with another selective contact. Of course, underincreased vehicle speed from the time the transmission has been shiftedinto low gear and the vehicle started in motion, the selectivecontact-carrying disc 99 will be progressively rotated in acounter-clockwise direction in respect to Fig. 8 in direct proportion tosuch increase in speed. Under this counter-clockwise movement, of theselective contact disc with respect to the selector contact 98, theselective contact 94 will be rotated out of engagement with the selectorcontact 90 and the selector contact 98 will pass first onto theinsulated space I05 between the contacts 94 and 95 and then onto theselective contact 95. As previously indicated, the disengagement of theselector contact 98 from the selective contact 95 will have no result,but engagement of the selector contact 90 with the selective contact 95will result in the transmission mechanisms being shifted out of firstspeed and into second speed. The sequence of operations resulting fromengagement of the selector contact 98 with the selective contact 95 willbe as follows: 1

A. The relay R2 will be energized through a circuit comprising the leadI39, contacts HI and I42 of the switch I43, the lead I39, selectorcontact 9B, selective contact 95, a lead I60 having interposed thereinthe now closed switches I31 of the relays R4 and R3 and the now closedswitch I36 of the relay RI, the coil of the relay R2 and the now closedcontacts IGI of a switch S2, and. the lead I41 back to the battery B,thereby energizing the relay R2 and closing the switches I33, I34 andI35 thereof and opening the switches I36, I31 and I38 thereof.

B. As a result of the closing of the switch I35 of the relay R2, theclutch-operating solenoid 90 will be energized through the same circuitas before described in connection with the operation of the clutch inshifting to first speed; it being noted that the clutch-solenoid-controlswitches I35 of the relays RI, R2, R3, and R4 are connected in parallelacross the leads I and I5I. The clutch will now be disengaged.

C. The moving of the clutch-operating mechanism to neutral position willcause the neutralizer-controlling switch I53 to be closed, which will inturn result in' the closing of the before described circuit of the coil10 of the neutralizer mechanism, which energizes the neutralizer coiland cause the magnetically influenced elements thereof to move to theirupper positions. Under this upward movement of the magneticallyinfiuenced elements of the neutralizer mechanism, the latch 86 willcarry with it the free end of the neutralizer lever 69, which will movethe neu tralizer fingers 66 and 66a together and cause, by engagement ofthe neutralizer pin 64 with the neutralizer finger 66,, the shifting ofthe low speed gear 52 to its neutral position. Of course, as soon as thelatch element 86 reaches its uppermost position, it will be pivotallyretracted. by the cam lug 09 out of engagement with and out of the pathof travel of the free end of 'the neutralizer arm 69, which will leavethe neutralizer am free to move pivotally downwardly withoutinterference by the neutralizer latch.

D. Also, as a result of the energization of the neutralizer coil 10 andthe upward movement of the magnetically responsive neutralizer elements,the switch I56-will be closed by the push rod I51, which will complete acircuit through the second speed shifting solenoid 0|, and which circuitwas initiated by the closing of the switch I33 of the relay R2. Thiscircuit of the second speed solenoid 6i is as follows: part of the leadI39, the lead I56, the lead I58, a lead I62 which includes the solenoidcoil 6I, the'switch- I33 of the relay R2, and a lead I63, the lead I58,the switch I56 and the lead I41. The shifter solenoid 6| now beingenergized will cause the armature bar 51 and parts coupled thereto tomove to their extreme left-hand positions, thereby shifting thetransmission mechanism from neutral into second speed and opening'thecontacts I6I of the switch S2 by engagement of one of the fingers withthe switch S2 by a switch-operating lug I66. This opening of thecontacts I6I of the switch S2 will break a holding circuit through therelay R2, which was closed by the switch I34 01 the.relay R2, justsubsequent to energization of the coil of the relay R2 by engagement ofthe selector contact 98 with the selective contact 95, and which circuitwas as follows: the lead I39 to the lead I46, the lead I65 havinginterposed therein the switch I36 of the relay R2, part of the lead M56(including the switches I31 of the relays Rd and R3 and the switch I38of the relay Rl and the coil of the relay R2 and contacts I95 of theswitch S22), and the lead I 41 back to the battery. This opening of theswitch contacts l6l not only opens the relay-holding circuit justdescribed, but also opens the initial relay-energizing circuit whichincluded the selector switch contacts 98 and 96.

E. As a result of this de-energization of the relay R2, the severalswitches thereof will be returned to their normal positions, which willresult in de-energization of the clutch-operating solenoid 99 whichpermits the clutch to return to its set driving position and which, inturn, results in opening of the switch E53.

F. This opening of the switch I53 de-energlzes the neutralizer solenoid19. The neutralizer sole noid 19, being now neutralized permits thereturn of the latch 96 to its lower normal position, dur-- ing whichmovement the latch will cam over the :iree end of the neutralizer arm 69and come to rest as shown, for example, in Fig. 5.

Of course, the vehicle will now be driven in second gear until theselector contact 98 engages some other one of the selective contacts 94,.96, or 91.

If we assume now that the vehicle increases speed in second gear andthat the acceleratorcontrolled selector contact is maintained stationcry and in a position radially inward of the neutral area I66 of theselective contact disc 99, itwill be obvious that the relative rotarymovement between the selector contact 98 and the selective contact willcause the selective contact 95 to be moved out of engagement with theselector contact 98 in a counterclockwise direction. Upon leaving of theselective contact 94 in a direction of increased speed, the selectorcontact will first engage the neutral strip I06 between the contacts 95and 98 and will then engage the selective contact 98. Due to the holdingcircuit for the relay R2, the transmission mechanism will be retained insecond speed until contact is actually made between the selector contact98.,

and the selective contact 98, at which time the transmission mechanismwill be shifted into third speed as a result of the following sequenceof operations:

A. The relay R3 will be initially energized, by

closing of a circuit comprising the lead I39, the

selector contact 98, the selective contact 96, a (I lead I66. (whichincludes the now closedswitches I31 of the relays RI and R2, the nowclosed switch I38 of the relay R4, the coil of the relay R3, and the nowclosed contacts I61 of a switch S3), and the lead I41 back to thebattery. As a result of this energization of the relay R3, the switchesI33, I34 and I35 thereof will be closed and the'switches I36, I31 andI38 will be opened.

B. The closing of the switch I35 of the relay R3 results in the closingof the before-described circuit of the clutch-operating solenoid 98,which will result in release of the conventional friction clutch andclosing of the switch 53.

C. The closing of the switch 53 as a result. of clutch-releasingmovements of the clutch-operating linkage results in closing of thebeforedescribed circuit through the relay 18, energization of whichrelay results in upward retraction of the latch 86 and consequentshifting out of second speed into neutral.

D. Also as'a result of energization of the neutralizer coil 18, theswitch I56 is closed and results in the final closing of a circuit forthe third speed shifter solenoid 58, which circuit was previouslyinitiated by closing of the switch I33 of the relay R2 and is composedas follows: a part of the lead I39 from thepositive side of the battery,the lead I50, the lead I58 to a lead I61 (which includes the shiftersolenoid 58 and the now closed switch 833 of the relay R3), the lead I63to the lead 558, the lead I58 from the lead I69to the switch 559, theswitch I56, and the lead M1 back to the battery. The transmissionmechanism will now be finally shifted into third speed and the contactsI 6? of the switch S9 will be broken, thereby interrupting the initialcircuit through the relay R3 which included the selector switch contacts98 and 96 and also interrupting a holding circuit through the relay R3,which latter was made previously as a result of the closing of theswitch I34 of the relay R9; This holding circuit, which has justbeeriopened by the breaking ofthe switch contacts I61, was composed asfollows: the lead I39 from the battery to the lead I48 to the lead I65,a lead I68 having interposed therein the switch I34 of the relay R3, thelead I66 (including the switches l31'of the relays RI and R2, and theswitch I38 of the relay R4 and the coil of the relay R3 and the contactsI6? of the switch S3), and the lead 541 back to the battery.

E. As a result of this de-energization of the relay R3, the severalswitches thereof will be returned to their normal positions, which willresult in de-energization of the clutch-operating solenoid 99 whichpermits the clutch to return to its set driving position and which, inturn,

results in opening of the switch I53.

F. This opening of the switch I53 de-energizes the neutralizer solenoid18. The neutralizer solenoid 18 being now neutralized permits the returnof the latch 86 to its lower normal position, during which movement thelatch will cam over the free end of the neutralizer arm 69 and come torest as shown, for example, in Fig. 6.

Now if, as a result of still further increased vehicle speed or changedaccelerator position,

the selector contact 98 is made to engage the fourth speed selectivecontact 91, the transmission mechanism will be shifted to fourth speed,

or direct drive in this instance, as a result of the-following sequenceof operations:

A. The lead I39, the selector switch contacts 98 and 91, a lead I69(which latter includes the now closed switches I38 of the relays RI, R2,and

B. As a result of the closing of the switch I35 of the relay R4, thecircuit of the clutch-operating solenoid 90 before described will beagain closed, resulting in energization of the de-clutching solenoid 90,which will result in release of the clutch and closing of the switchI53.

C. The closing of the switch I53 as a result of clutch-releasingmovements of the clutch-operating linkage results in closing of thebefore-described circuit through the relay 18, energization of whichrelay results in upward retraction of the latch 86 and consequentshifting out of third speed into neutral.

D. Also as a result of energization of the neutralizer coil 18, theswitch I56 is closed and results in the final closing of a circuit forthe fourth speed shifter solenoid 59, which circuit was previouslyinitiated by closing of the switch I33 of the relay R4 and is composedas follows: the lead I39 from the battery-to the lead I50, the lead I50,the lead I58,,part of the lead I82 to and through a lead I1I havinginterposed therein the fourth speed shifting solenoid 59 and the switchI33 of the relay R4, part of the lead I61 to the lead I63, part of thelead I58 from the lead I63 to the switch I56, the switch I56 and thelead I41 returning to the battery.

As a result of this energization of the solenoid 59, the transmissionmechanism will be shifted to fourth speed and the contacts I of theswitch S4 will be broken, thereby interrupting the energizing circuit ofthe relay R4 which was made through the selector switch contacts 94 and91, and also interrupting a holding circuit through the relay R4, whichwas initiated upon closing of the switch I34 of the relay R4. Thisholding circuit for the relay R4 which was just broken by opening of thecontacts I10 of the switch S4 was composed of the lead I39 to the leadI48, the lead I48 to the lead I65, part of the lead I65 to the lead I68,part of the lead I68 9. lead I12 including the switch I34 of the relayR4, part of the lead I69 (which includes the switches I38 of the relaysRI, R2 and'R3 and the coil of the relay R4 and the contacts I10 of theswitch S4), part of the lead I66, from the lead I69 to the lead I41, andthe lead I41 returning to the battery.

E. As a result of this de-energization of the relay R4, the severalswitches thereof will be returned to their normal positions, which willresult in de-energization of the clutch-operating solenoid 90 whichpermits the clutch to return to its set driving position and which, inturn, re-

- sults in opening of the switch I53.

F. This opening of the switch I53 de-energizes the neutralizer solenoid18. The neutralizer solenoid 18 being now neutralized permits the returnof the latch 86 to its lower normal position, during which movement thelatch will cam over the free end of the neutralizer arm 69 and come torest as shown, for example, in Fig. 6.

The manual switch I40 is normally closed both during times of operationand during times of inoperativeness, but is opened for the purpose ofrendering the automatic shifting mechanism inoperative to shift thetransmission out of any selected speed ratio that it will be in at thetime switch I40 is opened. In fact, if this switch I48 is opened whenthe transmission mechanism is in any one of its four speed ratios, themechanism will stay in that speed ratio and. the automatic mechanismwill be inoperative to shift either out of that ratio or to shift intoanother ratio. However, if the switch I40 be opened at a time that thetransmission mechanism is in 7 neutral, there will be no immediateeffect in that the mechanism will be free to shift in to the firstsubsequently selected ratio and will be retained in that ratio until theswitch I40 be manually opened, except, however, that the transmissionmay be manually neutralized while the switch I40 is opened. This switchI40 simply serves, when closed, to shunt around a series of normallyclosed switch contacts I12 of switch SI, S2, S3 and S4, which areserially interposed in lead I39 when the switch I40 is open. The severalswitch contacts I12 are serially interposed in a lead I13 that extendsfrom one side of the switch I40 back to the other thereof.

The two position manual switch I43 is under all normal conditions leftin the position shown in Fig. 7 wherein the contacts I and I42 thereofare closed, but the contact I4I thereof can be moved out of engagementwith the contact I42 and into engagement with a contact I14 thereof forthe purpose of shunting out the selector switch 93 and energizing acircuit through the coil of relay R4 entirely independent of the switch93 and which comprises the following, to wit, lead I39 through switchI40 and contacts HI and I41 of switch I43; lead I15 to lead I69 at apoint after the selector switch, lead I69 through the switches I38 ofrelays RI R2, and R3 and through relay coil R4 and through contact I10of switch S4 to lead I66, lead I66 to lead I41 and lead I41 back to thebattery. Of course, as soon as the shift is made as a result ofenergization of shift solenoid 59 into fourth gear or speed, this lastmade shifter circuit through solenoid 59 will be automaticallyinterrupted by opening of contacts I10 of switch S4 so that thetransmission mechanism will essentially remain in fourth gear untilswitch contact MI is returned to engagement with contact I42 of switchI43, although the transmission is subject to manual neutralization. Itwill be obvious that, whereas switch I43 shows only means for manuallyselecting the fourth speed ratio of the transmission that additionalswitch contacts and cir- 'cuits could be provided in identically thesame manner for manually selecting any desired number or, in fact, allof the several speed ratios.

The energization circuit of each of the relays RI, R2, R3 and R4 isserially connected with one or the other of normally closed switches I36, I31, and I38 of each of the other three relays. The purpose of thisis to positively render three of the four relays inoperative until allthe functions assigned to the operation of a previously energized relayhave been completed and the first energized relay de-energized. This isa safety feature designed to prevent accidental simultaneous orover-lapping shifting of the transmission mechanism into two speeds as aresult of very rapid movement of the selector contact 98 into successiveengagement with different selective contacts.

Now that the complete operation of the entire mechanism, as a result ofengagement of the selector contact 98 with each of the several selectivecontacts is understood, a brief summary periphery toward the axis of theof the operation of the mechanism appears to thermore, it should benoted in connection with be in order to enable the reader to see moreclearly the numerous advantageous functions resulting from the novelstructure and arrangement of parts described.

Summary ration By particular reference to Fig. 8, it will be seen.

, non-radial, that is, at least, with the exception of one side ofselective contact 94 which is on a radial line very close to the radialline indicated at zero miles per hour. Furthermore, it will be noted byreference to Fig. 8 that each of the selective contacts is of varyinglength, in terms of degrees of rotary movement between the selectorcontact and selective contacts at different radially spaced pointsthereon.

At this point, attention is called to the fact that radially spacedconcentric broken line circles on Fig. 8 indicate different percentagesof accelerator advancement from an idling position toward a position offull throttle. It is also important to note that in the particularembodiment illustrated in Fig, 8, that the several selective contacts 94to 91 inclusive are not only of varying length in a rotary direction atdifferent radially spaced points, but that the distance, in terms ofdegrees, of relative rotation between the selector and selectivecontacts, between each of the circumferentially spaced leading orshifting edges of each successively engaged selective contact undereither direction of rotation between the selector and selective contactsis progressively greater from the periphery toward the axial portion ofthe contacts.

Still further, it will be seen by reference to Fig. 8, that thecircumferential distance, in terms of rotary movement between theselector and selective contacts, .in which any speed ratio can bemaintained in a direction of rotation caused by increased speed is notonly increased from the contacts, but is actually shifted bodily withinthe overall vehicle speed range of rotation of the disc 99.

From the facts analyzed above and from careful examination of Fig. 8, itwill be seen that it is possible by properly designing the selectivecontacts to automatically shift the transmission mechanism from onespeed ratio to another in such relation to vehicle speed and enginepower output demand, the latteras determined by accelerator. position,that the engine will at all times be operated as closely as possible atits most efficient speed under all different power output demandconditions, consistent with the limitation imposed by the number ofspeed ratio steps available. For example, it will be seen that at thatpoint of acceleration where the selector contact passes oil of theneutral area I08 into the rotary path of the several selective contactsthe total vehicle speed range required to shift through all four of thetransmission speed ratios occupies a circumferential space on theselective contact disc representing only approximately six M. P. H. ofvehicle speed, and it will also be seen that under conditions of maximumacceleration, at which time the selector contact would be on the brokencircle marked 100 per cent ,throttle ad vancement, the total vehiclespeed range required toshift through the four speed ratios occupies acircumferential space representing approxi- 100 percent acceleratoradvancement.

Fig. 8, that the speed range inwhich any one of the speed ratios will bemaintained increases with accelerator advancement, and that the speedrange in which successive speed ratios are maintained is successivelygreater for each speed ratio from one to four.

Preferably the arrangement is such that at any degree of the advancementof the accelerator, and during increasing speed, the ratio of the speedat which shift will be made out of first speed and into second speed tothe speed at which shift will be made out of second speed and into thirdspeed, is equal to the ratio of the reduction of the second gear in thetransmission to the reduction of the first gear in the transmission.This relative arrangement is deemed highly important in that it enablesthe selector switch mechanism to be so designed with respect to thecharacteristics of any particular engine that the power output of theengine will be as closely balanced to the load demand as is possible,consistent with the limitation imposed by the number of speed ratiosteps into which the transmission or shifting mechanism is divided.

By reference again to Fig. 8, it will be seen that under increasingvehicle speed from zero and consequent counter-clockwise rotation of theselective contact-carrying disc, the transmission mechanism will beretained in low gear through approximately 99 degrees ofcounter-clockwise rotation of the selective contact-carrying disc fromits zero position, and which represents approximately 83 M. P. H. ofvehicle speed. Under these conditions of'maximum acceleration, theselective contact 98 will, of course, be positioned on the smallestbroken line circle identified as Of course, under this condition ofmaximum acceleration, the shift to second speed will not take placeuntil the vehicle speed of approximately 33 M. P. H. is attained; andthe shift from second to third speed would not be attained until theselector contact 98 passed off of theselective contact 95 and on to theselective contact 96, which would mately 165 degrees of come about at avehicle speed of approximately M. P. H., at which time the selectivecontactcariying disc would have passed through approxicounter-clockwisemovement; and the shift out of third speed into fourth speed will bebrought about at a vehicle speed of approximately 85 M. P. H., at whichtime the selective contact-carrying disc will have passed throughapproximately 255 degrees of counterclockwise movement from zero speedposition.

With an understanding of the action of the device under fullacceleration as above described, it is interesting to compare thisaction with the action of .the device under conditions approachingmately 85 miles per hour vehicle speed. Fur- -M. P. H. vehicle speed,

minimum acceleration, or at a time, for example, when the selectorcontact 98 is positioned on the broken line circle marked 20 percentacceleration. Under this last named'condition of acceleration andincreasing speed from zero, it will be seen by reference to Fig. 8, thatfirst speed will be maintained through onlyv about 25 degrees ofrotation and about 24 M. P; H. vehicle speed, at which point the shiftfrom first to second will take place as a result of only about 42degrees of counterclockwiserotation, or approximately 14 and that theshift from second speed to third speed will take plate at approximately58 degrees of counter-clockwise fourth speed will take place as a resultof approximately '10 degrees of counter-clockwise movement of the disc99, or at about 23 M. P. H.

.On Fig. 8, arrows extending between different circumferentially spacedbroken radial lines are marked to indicate the various different vehiclespeeds between which shifts may be made from all different speed ratiosto the next adjacent speed ratios under either increasing or decreasingvehicle speed, as a result of varied degrees of acceleration fromminimum to maximum.

Another important feature in connection with Fig. 8 is the neutral areaI08 on which the selector contact 98 is positioned at all times underconditions of minimum acceleration, and which permits shifting out ofany previously selected speed ratio and into any other selected ratiowithout passing through any intermediate ratio.

Description and operation Figs. 9 and 10 In Fig. 9, the selector contactis indicated by 98a, the spring contact finger carrying the contact 98ais indicated by mm, and th selector contact-carrying guide bar isindicated by I03a. These elements 98a, Ma, and W311 ar respectively likethe elements 98, I04, and I03 of Figs. 1, 2, and 8. In fact, in Figs. 9and 10, the entire selector switch mechanism indicated as an entirety by93a, is adapted to be employed as a substitute for the switch mechanism93 of the before described figures and hence parts thereof whichcorrespond operatively to certain parts in the before described figuresare indicated by the same characters, plus the exponents a. In theselast figures the selective contact carrying element indicated by 99a, isin the nature of a rotatable drum carrying on its periphery contact-s99a, 95a, 96a, and 9Ia, which corresponds respectively to the selectivecontacts 94, 95, 96, and 9'! of Fig. 8, and respectively representsfirst speed, second speed, third speed, and fourth sp ed. In thisarrangement, the drum is rotated in exactly the same manner as is thedisc 99 of Fig. 8, and the selector contact is moved on a line parallelto the axis of the drum. The drum 99a is shown as mounted fast on ashaft I20a that is the equivalent of shaft I20 of Fig. 1, and whichshaft may be assumed to be operated from the governor I09 of Fig. 1through a pinion gear II 9a, and a gear rack II8a, said elements II9aand HM respectively corresponding to the figures I I9 and H8 of Fig. 1.In Fig. 10, wherein the selective contact carrying face of the drum isillustrated in flat form, the operation of the device is illustrated asbeing very closely analogous to that of the selector switch mechanism ofFigs. 1 to 8 inclusive. It may be said, however, that in Fig. 10vertical broken lines are equivalent to the broken radial lines of Fig.8, and that the longitudinal broken lines are equivalent to thecircumferential broken lines of Fig. 8. From analysis of Fig. 10, itwill be obvious that the selector contactmechanism could be constructedwith a flat selector contactcarrying surface just as illustrated in Fig.10. In which case, it would simply be necessary to move this surfacelongitudinally of Fig. 10 under variation in vertical speed, or at leastto provide relative movement between selective and selector contacts inthis direction. This being just one of numerous possible modifications.

These Figs. 11 to 13 inclusive illustrat still a different form ofselector switch mechanism, which being adapted to be substituted for theswitch mechanism of Figs. 1 to 8 inclusive, is indicated as an entiretyby the same numeral as the selector mechanism of Figs. 1 to 8, plus theexponents b, and the various elements thereof are, insofar as possible,indicated by numerals assigned to the corresponding parts in Figs. 1 to8 plus the exponents b.

In this selector switch 93b, the selective contact-carrying elementis inthe nature of a piv oted arm 99?: that is pivotally anchored to a slidebar I20b'. This contact-carrying arm, 992), which may be assumed to beof insulating material, is provided with selective contacts 94b, 95b,96b, and 91b, that respectively correspond to the selective contacts 94,95, 90, and 91, of Fig. 8. The selector contact of this last switchmechanism indicated by 98b is mounted directly on the end of acontact-carrying bar I041), that is formed with gear teeth and isaxially slidably mounted in bearings I04'b. This contact-carrying bar ismoved in respect to accelerator advancing and retarding movementsthrough a range including a gear rack I03b and an integrally formed pairof gears I030, and I03d-, which respectively mesh with I03b and I041).The element I03b may be considered as the equivalent of the element I03of Figs. 1 and 2, and would be connected'up to the accelerator range inidentically the same manner. The slide bar I20b is guided for straightline movements on guide flanges I200. The guide bar I20b is moved backand forth over the guide flanges I200 under variations in vehicle speedbetween stops I 20d by means of a governor I09b that is like thegovernor I09 of Fig. l, and the shaft I I4b, of which may be assumed tobe driven from the shaft 31 of Fig. 1 through connections shown in Fig.l for driving shaft H4. Of course, the contact arm 99?) is moved on astraight line path of movement with the guide bar I20b. This contact armis pivotally movable on the guide bar between the extreme positionsshown in Fig. 12 and is limited in pivotal movements in acounter-clockwise direction by engagement with cooperating stops 991). Aspring I23b, which roughly corresponds to the spring I23 of Fig. 2 isprovided for yieldingly biasing the contact arm to move pivotally in thedirection of engagement of stops 99b. The guide bar I20b is anchored byan arm I20b' to the element IIGb of the governor 10%. Through the actionof the governor spring II'Ib, the guide bar is yieldingly biased in itsextreme position against the lower stop I20d, and as a result ofcentrifugal action of the governor. is progressively moved upwardlytoward the upper stop 1201) under increased vehicle speed from minimumtoward maximum. Under conditions of minimum acceleration and zerovehicle speed, the several parts of the switch mechanism 9917 will bepositioned as indicated in Fig. 11, in which figure it will be notedthat the selector contact 99b is slidingly retracted away from thecontact arm 9917, but is opposite the first speed selector contact 9412,the space between the contact surfaces of the contact arm and theselector contact 98b being functionally the equivalent of the neutralarea I08 of Fig. 8. To effect a shift into first speed from neutral atzero speed, the operator will simply accelerate the engine slightly,which will bring the selector contact 9817 into initial engagement withthe selective contact 94b. This will, of course, start the vehiclemoving in a forward direction in first speed. Further advancement of theaccelerator after initial engagement of contact 99 with the selectivecontact arm will result in counter-clockwise pivotal movements of theselective contact arm 99b,

which pivotal movements will tend to produce a relatively slidingmovement of the selector contact 94b toward the top of the contact armover the surface of low speed contact 941:, but this relative slidingaction toward the free end of the contact arm will soon be offset and,in fact, reversed as a result of increased engine speed, which willcause bodily upward movements of the contact arm and a relative pivotalmovement thereof back toward its normal position. Under further normaladvancement of the accelerator and a normal resultant rate of vehiclespeed increase the selector and selective contacts will advance at anapproximately uniform rate, any differences being taken up by pivotalaction of the arm, on straight line paths that diverge one toward theother, and this divergence will result in relative sliding movement ofthe selector contact 98b over the engaged surface of the contact arm ina direction from the top toward the bottom of the arm, which, ifcontinued, will result in successive engagement of the selector contact881) with the selective contacts 95b, 96b, and 91b. Thus successiveengagement will, of course, result in a successive shifting through theseveral transmission speed ratios in a manner similar to the mannerdescribed in Figs. 1 to 8. However, should the operator rapidlyaccelerate at the time when the selector contact 98b is in engagementwith any of the selective contacts 95b, 96b, or 91b, a pivotal movementof the arm 99b will follow, and this will. result in a rapid slidingaction of the contact 98b toward the free end of the contact arm, whichwill be of such extent as to produce a shift into the next lower speedrange or in some instances, through two or more lower speed ranges. Inthis switch mechanism, as in previously described mechanisms, it ispossible to shift from any speed ratio into any other speed ratiowithout passing through any other immediate speed ratio due to the factthat the selector contact 88b will always retract away from the contactarm under some degree of deceleration and may be brought back intoengagement with the receleration under a different speed conditionwherein it will re-engage the contact arm on a different selectivecontact.

Furthermore, in this structure, as in others, the vehicle may be broughtto a stop without shifting out of the last selected speed ratio.

In the particular arrangement illustrated in Figs. 11 to 13 inclusive,the straight line paths of movement of the selective switch arm 99b andselector contact 98b diverge in the direction of increased speed at anangle of approximately 45 degrees, the contact arm is mounted forpivotal movements through an arc of approximately 45 degrees between aposition wherein it is substantially parallel to its straight line pathof movement to a position wherein it diverges outwardly from itsstraight line path of movement at an angle of approximately 45 degrees,and said switcharm, when in its pivotal outer or normal position, isdisposed at approximately 90 degrees with respect to the path ofmovement of. the selector contact. 7 Of course, this angle of thecontact arm to the path of movement of the selector contact is variedunder accelerating movements of the selector contact of such extent asto produce pivotal movements of the switch arm and this is highlyimportant in that it results in the automatic shifting into lower spedranges under heavy acceleration.

Referring back again to Figs. 1 to 8 inclusive, attention'is directed tothe factthat the dash pot I24, sealing cup of piston I25, and slipconnections I28 and I29 are provided for the purpose of retardingdecelerating movements of the selector contact so as to avoidunnecessary rapid shifting through one or more successively higher speedranges under very rapid but brief periods of deceleration.

'What I claim is:

1. The combination with an engine having a manually operated speed andpower controller, a driven member, a variable speed transmissionmechanism interposed between the engine and driven member and having aplurality of speed change ratios, of power-operated means for shiftingthe transmission mechanism from one speed change ratio to another,either in an upshift or downshift direction, and a control mechanism forthe power-operated shifting means including a plurality of controlcircuits each representing a different speed ratio condition of thetransmis- 30 the contacts of the first noted class to control adifferent one of said circuits, driven member speed controlled meansautomatically effecting relative contact selecting movements between thecontacts of the first class and the single contact of the second classand means responsive to was made.

movements of the engine speed and power controller also providingrelative contact selecting movements between the contacts of the firstclass and the single contact of the second class, and so constructedthat the interval in terms of driven member speed between any twoupshiftlng operations of the transmission mechanism grows progressivelygreater with the advancement of said engine power and speed controller,the rate of increasein size of said intervals being determined by thecorresponding speed change ratios.

in said transmission mechanism from which said shifts are made.

2. The structure defined in claim 1 so devised that for any given degreeof advancement from minimum to maximum of the said speed and powercontroller, the ratio of the driven member speed at which one upshif-tin the transmission mechanism is made to the driven member speed atwhich the next successive upshift is made, is the same as the ratio ofthe transmission speed change ratio from which the second shift was madeis to the speed change ratio from which the first shift was made.

. 3. The structure defined in claim 1 so devised that, given the drivenmember speed of any particular upshifting operation, the driven memberspeed of any successive shift in the same direction can be determined bythe multiplying of the driven member speed at said first shift by theproduct of the degree of advancement or retardation of the engine powerand speed controller from the position at first said shift, and theratio of the reduction of the speed change ratio in the transmissionfrom which the first shift was made to the reduction of the speed changeratio from which the succeeding shift WENDELL B. THOMAS.

